1. Field of the Invention
This invention relates in general to certain new and useful improvements in needle tip protective devices, and more particularly, to needle tip protective devices which are capable of being used with a large number of supports without requirement of a special support construction and usually without special attachment means therefor.
2. Brief Description of the Prior Art
For many years the medical profession has utilized a variety of medical devices for puncturing the skin to enable delivery or removal of fluid from a patient's body and which are generally referred to as "needles". The structure of such needles has varied substantially depending on treatment indicated. One type of needle construction, with which the needle tip protective device may be used, is generally referred to as hypodermic needles and which comprises a reservoir suitable for accommodating fluid. This hypodermic needle is also equipped with movable piston utilized to expel the fluid from the reservoir through an aperture in the reservoir. In the most common construction, the reservoir is an elongate cylinder having a slideable push rod coupled to the piston and an aperture at the opposite or distal end. An elongate hollow cylindrical needle is sealingly coupled to the reservoir end and the aperture therein and terminates in a sharp point configured to readily puncture the patient's skin.
In normal use, a quantity of an infusion fluid is drawn into the reservoir of the hypodermic needle after which air is expelled by discharging a small amount of the infusion fluid out through the needle. Thereafter, the needle point is inserted through the skin and, in most cases the blood vessel wall of the patient. The infusion fluid is then expelled out through the needle by movement of the push rod and piston.
In addition to the use of hypodermic needles for injection of substances into the patient, a similar device often referred to as a Vacutainer may be employed to perform the function of withdrawing a fluid sample, such as blood, from the patient. The Vacutainer comprises a housing sized to receive a blood or other body fluid tube and which is provided with a stopper on the end thereof. Moreover, the tube is under a vacuum. A double pointed needle is connected to the housing with one sharp pointed tip adapted for insertion into a patient's body and typically into a vein or artery. The other tip extends into the housing and arranged to extend through the stopper when the sample tube is introduced into the housing. In essence, when the needle portion of the Vacutainer is inserted into the patient and the opposite needle end communicates with the sample tube, the vacuum within the sample tube draws the desired body fluid into the tube. Once the desired quantity of body fluid has been drawn into the tube, the needle is removed.
Another basic type of needle construction utilized by medical practitioners is referred to as an intravenous catheter and intravenous catheter placement needle combination. In general, these intravenous catheter systems comprise two basic system parts, the intravenous catheter itself and an intravenous catheter placement needle. The intravenous catheter comprises a housing which supports an outwardly extending generally thin hollow tube. The intravenous catheter is configured to receive an intravenous catheter placement needle similar to, but of generally thinner cross-section and of shorter length, than the hypodermic needle. The intravenous catheter and intravenous catheter placement needle are constructed to permit the intravenous catheter placement needle to be inserted through the intravenous catheter housing and extend through and beyond the intravenous catheter tube. When so assembled, the intravenous catheter and intravenous catheter placement needle form a single unit which terminates in the outwardly extending intravenous catheter placement needle having a sharp piercing point and a surrounding intravenous catheter tube.
In use, the intravenous catheter and intravenous catheter placement needle assembly are inserted into the patient's blood vessel by inserting the intravenous catheter placement needle point and intravenous catheter tube end through the patient's skin and blood vessel walls similar to a hypodermic needle or Vacutainer insertion. In contrast to a hypodermic needle use however, the intravenous catheter placement needle is then withdrawn from the intravenous catheter assembly leaving the intravenous catheter tube within the patient's blood vessel. Once the intravenous catheter placement needle is withdrawn, a tube is attached to the intravenous catheter in a sealing manner and is coupled to a supply of the fluid which is to be introduced into the patient's system.
In accordance with modern medical technology, essentially all needle constructions are sterilized and maintained in a sterile condition prior to their use with patient. In most instances, the majority of needles utilized today by modern medical practitioners are actually manufactured, sterilized, wrapped in a sterile package and used a single time and discarded after use. Since the needles are initially sterile, their handling during use by medical practitioners prior to any contact with the patient does not represent any substantial health hazard to the practitioner. However, while the use of sterile needles provides protection to the patients during the time the needles are used, the contamination of the needles by the patient's system during use transforms the previously sterile needles into a potentially dangerous object for the medical professional. Because the needles are generally manufactured of a high quality surgical-type steel, they readily maintain their sharp pointed condition after use. As a result, a potential exists for inadvertent or accidental piercing of the skin of the medical professional handling the needles subsequent to use on a patient.
Because many diseases, such as hepatitis or acquired immune deficiency syndrome (AIDS), etc., are readily transferrable by inadvertent or accidental puncturing of the user's skin with a contaminated needle, a substantial danger is presented to members of the medical professional through use of such needles. This problem is exacerbated by the environment in which the medical professionals function, in that frequently needles are used and handled in distracting or stressful environments, and in some instances in emergency situations.
To meet this problem and reduce the danger presented to medical professionals by the use of needles, manufacturers have provided various needle covering caps and similar structures with the intent that the needle cap be replaced by the professional immediately after withdrawing the needle from the patient. While such replacement caps and the like do provide protection of the professional by covering the needle point, it has been found that the medical professional often fails to take the time to replace the cap in order to protect themselves or others from inadvertent skin piercing or scratching. In addition, the very act of returning the needle cap to the needle in itself often presents a substantial danger of piercing the medical professional's skin with a potentially contaminating result.
One of the significant problems with most of the commercially available needle tip protective devices is the fact that the protective device must be specially constructed for use with a particular needle support such as a particular hypodermic needle or intravenous catheter system or the like. Otherwise, most needle apparatus manufacturers must specifically design their needle apparatus in such manner as to accommodate and be used with a conventional needle tip protective device. There are generally no commercially available needle tip protective devices which are universally usable with a large number of syringes. More specifically, there are no commercially available needle tip protective devices which are usable with intravenous catheter placement needles, hypodermic needles or Vacutainer devices and which do not require a special construction or adapter for use with each.
There have been several proposed needle tip protective devices for use in shielding needles on various supports, but each of these proposed protective devices suffers from one or more of the limitations as mentioned above. U.S. Pat. No. 3,134,380 to Armao discloses a needle tip protective device which is used with a hypodermic needle. However, in the Armao patent, the device itself is constructed only for a particular type of hypodermic needle and must be used only with a syringe having a specific hub size. Otherwise, in order to accommodate different sized syringes, numerous needle tip protective devices must be provided in accordance with the Armao construction. In addition, in the Armao construction, the cap which covers the distal end of the needle having the sharp point is intended to be removable such that removing and replacement of the cap is required.
U.S. Pat. No. 3,354,881 to Bloch also discloses a compressable device adapted to extend over the shank of a needle and is adapted with a rubber septa at each of the opposite ends and which is designed to be placed over and surround a hypodermic needle. However, this device is intended to be removable from the needle and is not disposable with the needle. Moreover, a device of the type taught in the Bloch patent is intended primarily for re-usable needles.
U.S. Pat. No. 4,139,009 to Alvarez also discloses a needle tip protective device and comprises a permanently attached cover surrounding the needle with a number of elastically resilient arms which extend along the length of the needle. These arms are constructed so as to bow outwardly from the shank of the needle when the needle is pressed against the skin of the patient. Moreover, there is no separately removable cap covering the tip of the needle. In addition, and in the Alvarez construction, the needle must be attached directly to a hub portion of a syringe which again limits the universality of use.
U.S. Pat. No. 4,660,570 to Dombrowski also discloses a needle tip protective device extending over a hypodermic needle and which includes a membrane extending over the sharp point of the needle. This membrane is intended to be pressed against the skin such that the needle extends through the membrane and through the skin of the patient in use.
U.S Pat. No. 4,650,468 to Jennings, Jr. also discloses a needle tip protective device for use with a hypodermic needle and which includes a sleeve concentrically disposed about the needle shank. The Jennings, Jr. construction also utilizes a safety shield at one end with a rubber membrane extending across an opening in the shield and which is adapted to be pierced by the sharp point of the needle when in use.
There are other U.S. patents which show needle protective devices such as the Brunet U.S. Pat. No. 4,553,962, the White U.S. Pat. No. 2,876,770 and the Sagstetter et al U.S. Pat. No. 4,664,653, each of which do not overcome the numerous problems as mentioned above in connection with the prior art needle tip protective devices. As a result, there still remains a need for an easy to use, simple and effective needle tip protective device which is universally usable with a wide variety of hypodermic needles, Vacutainers and intravenous catheter placement needles and the like without requiring a special support or construction therefor.